A New Orbiting Deployable System for Small Satellite Observations for Ecology and Earth Observation

In this paper, we present several study cases focused on marine, oceanographic, and atmospheric environments, which would greatly benefit from the use of a deployable system for small satellite observations. As opposed to the large standard ones, small satellites have become an effective and affordable alternative access to space, owing to their lower costs, innovative design and technology, and higher revisiting times, when launched in a constellation configuration. One of the biggest challenges is created by the small satellite instrumentation working in the visible (VIS), infrared (IR), and microwave (MW) spectral ranges, for which the resolution of the acquired data depends on the physical dimension of the telescope and the antenna collecting the signal. In this respect, a deployable payload, fitting the limited size and mass imposed by the small satellite architecture, once unfolded in space, can reach performances similar to those of larger satellites. In this study, we show how ecology and Earth Observations can benefit from data acquired by small satellites, and how they can be further improved thanks to deployable payloads. We focus on DORA—Deployable Optics for Remote sensing Applications—in the VIS to TIR spectral range, and on a planned application in the MW spectral range, and we carry out a radiometric analysis to verify its performances for Earth Observation studies

An approach to prevent frailty in community dwelling older adults: a pilot study performed in Campania region in the framework of the PERSSILAA project

We developed and tested an innovative physical training method in older adults that embeds the gym program into everyday life in the most conservative way possible. Physical training was included in the activities of local parishes where older women from Southern Italy spend most of their free time and was delivered by trained physical therapists with the support of an ICT tool known as CoCo. 113 older women (aged 72.0 [69.0-75.0] years) noncompliant to conventional exercise programs participated to the study. 57 of them underwent the final anthropometric assessment and 50 the final physical tests. In study completers handgrip strength and physical performance evaluated with the chair-stand, the two minutes step and the chair-sit and -reach tests significantly improved. Quality of life as evaluated with the EuroQol-5dimension (EQ-5D) questionnaire improved as well. In conclusion, a training program designed to minimally impact on life habits of older people is effective in improving fitness in patients noncompliant to other to physical exercise programs

Fiber optic fabry perot pressure sensor based on commercial ferule

In this study, we show an extrinsic pressure sensor consisting in a Fabry-Perot cavity realized on single mode fiber tip. The first mirror is given by the end of the optical fiber, that accurately cut, acts as reflecting mirror. The other one is made of a thin and elastic metallic diaphragm. Stressed by an external pressure, the metallic diaphragm bends, changing the optical cavity length and, therefore, the characteristics of the reflected signal. The holder structure, which allows the alignment of the fiber tip and reflecting diaphragm, is a commercial zirconia ferrule with external diameter of Dex = 2.5 mm. Although its construction procedure results simple and cheap, the results show performance comparable to more complex and expensive configurations. By using an aluminium plate as reflecting diaphragm of 100 μm thickness, sensitivity ranging in the 70-130pm/mmHg is experimentally demonstrated

A simple Fabry-Perot pressure sensor fabricated on fiber optic tip

In this work, we demonstrate an extrinsic pressure sensor realized on single mode fiber tip by means of simple fabrication steps and with low-cost instrumentations. The sensing element consists in a Fabry-Perot cavity: one reflecting surface is the end of the optical fiber, precisely cut, and the other one is a metallic diaphragm. Under the action of the external pressure, the metallic diaphragm bends changing the optical cavity length and, consequently, the characteristics of the reflected signal. The holder structure, which allows the alignment of the fiber tip and reflecting diaphragm, consists in a commercial zirconia ferule with external diameter of Dex = 2.5 mm. Despite its simplicity and cost-effectiveness, the achieved results show performance comparable to more complex and expensive configurations. By using an aluminum plate as reflecting diaphragm. sensitivity ranging in the 70-130pm/mmHg is experimentally

Strain Monitoring of a Composite Drag Strut in Aircraft Landing Gear by Fiber Bragg Grating Sensors

This work reports on the use of Fiber Bragg Grating (FBG) sensors integrated with innovative composite items of aircraft landing gear for strain/stress monitoring. Recently, the introduction of innovative structures in aeronautical applications is appealing with two main goals: (i) to decrease the weight and cost of current items; and (ii) to increase the mechanical resistance, if possible. However, the introduction of novel structures in the aeronautical field demands experimentation and certification regarding their mechanical resistance. In this work, we successfully investigate the possibility to use Fiber Bragg Grating sensors for the structural health monitoring of innovative composite items for the landing gear. Several FBG strain sensors have been integrated in different locations of the composite item including region with high bending radius. To optimize the localization of the FBG sensors, load condition was studied by Finite Element Method (FEM) numerical analysis. Several experimental tests have been done in range 0–70 kN by means of a hydraulic press. Obtained results are in very good agreement with the numerical ones and demonstrate the great potentialities of FBG sensor technology to be employed for remote and real-time load measurements on aircraft landing gears and to act as early warning systems

Hot-Wire Anemometer Based on D-Shaped Optical Fiber

This article proposes a hot-wire anemometer based on optical fiber embedding a fiber Bragg grating (FBG) and having a D-shaped transversal Section on whose flat surface a thin metallic layer has been deposited. Due to this geometrical structure, the optical power flowing through the fiber core can achieve the metallic layer and can be converted into heat. The embedded FBG can measure the resulting temperature increase and the temperature fluctuation of the D-fiber caused by the wind flowing. Numerical simulations have been performed in order to select the appropriate design parameters, such as thickness of the metallic layer and its distance from the core. Then, the fabrication process of the device and the experimental results of its characterization in temperature and wind assess its working principle. The developed sensor can work at low power levels of the source and is characterized by small size and high accuracy. Furthermore, it shows high cost-effectiveness and the possibility to modulate its wind sensitivity by setting the source power

Self-assembled colloidal photonic crystal on the fiber optic tip as a sensing probe

This paper presents an effective and efficient method to fabricate novel fiber optic sensing probes. The new, simple, and low cost approach is based on a 3-D photonic crystal dielectric structure directly deposited on the tip of a multimode optical fiber through the self-assembly of colloidal crystals (CCs) via a vertical deposition technique. Here, the CC is made of polystyrene nanospheres with 200 nm diameter, and the optical fiber is a UV-vis fiber with a core diameter of 200 μm. The obtained fiber probes exhibit a resonant peak at 480 nm and an amplitude enhancement of 3.7 with respect to the bare fiber; these results are highly repeatable. A numerical tool based on a finite element method analysis has been developed to study and analyze the 3-D subwavelength structures. Numerical results are in good agreement with the observed experimental spectra. Moreover, refractive index measurements have been carried out, revealing a sensitivity of up to 445 nm/RIU in the 1.33-1.36 values range. The achieved performances, which have been obtained by using very small active areas and an easy and reliable fabrication procedure, demonstrate the future perspectives of these fiber-optic probes for chemical and biological sensing applications